Book skew clamping method and device

ABSTRACT

A method for producing a profiled spine in a book having a first side defining a first plane, a second side defining a second plane and a spine. The method includes clamping the book using a first clamp element contacting the first side and the second clamp element contacting the second side and moving the first element with respect to the second element so as to skew the spine by moving at least one of the first side in the first plane and the second side in the second plane.

BACKGROUND OF THE INVENTION

[0001] The present invention relates generally to printed materials andmore particularly to clamping devices and trimming units for trimmingedges of a book.

[0002] U.S. Pat. No. 6,030,163 discloses a method for fusing two or morepieces along an edge to produce a volume. The volume can have a skewedspine.

[0003] U.S. Pat. No. 5,086,681 discloses transferring books using aninfeed conveyor system having a belt. The belt travels at slower speedthan conveyor chains to create a slight frictional force on pushermembers attached to the conveyor chains. As the books leave the infeedconveyor system, they are impelled into a first trimming station.

BRIEF SUMMARY OF THE INVENTION

[0004] A problem associated with prior art trimmers used for trimmingbooks is the delamination of the cover of a book from the interior sheetmaterial. This trim defect is typically called “chipout”.

[0005]FIGS. 1 and 2 show a force vector analysis by the presentinventors, in which the forces of a straight trim blade at an anglealpha are analyzed as a trimming blade 10 with a straight edge 12 cutsan end of a book 20. Book 20 includes sheet material 26 and a cover 22,connected to sheet material 26 by adhesive 24.

[0006] A resultant force FR normal to the blade edge 12 results, with aforce component F1 parallel to a tangent line of the cover interactionwith the sheet material 26, and a component FN normal to the tangentline. As shown in FIG. 1, as the blade 12 first cuts at the top of thebook 26 and cover 22, the normal force FN is directed into the book. Atthis stage, generally no chipout occurs.

[0007] However, as shown in FIG. 2, as the cut progresses through thelower curved section 28 of cover 22, the normal force FN acting on cover22 is directed away from sheet material 26, and can cause chipout, sincethe force is directed away from the sheet material 26.

[0008] One object of the present invention is to provide a method forproducing a skewed spine in a book. Anther alternate or additionalobject of the present invention is to improve cutting of books,especially of the sides of books adjacent to the spine. Anotheralternate or additional object of the present invention is to reducechipout in reciprocating blade trimmers.

[0009] European Patent Application No. 1 153 872, which corresponds tocommonly-assigned U.S. patent application Ser. No. 09/570,203 filed May12, 2000, discloses creating a skew in a collated sheet product.

[0010] The present invention provides a method for producing a profiledspine in a book having a first side defining a first plane, a secondside defining a second plane and a spine, the method comprising thesteps of:

[0011] clamping the book using a first clamp element contacting thefirst side and the second clamp element contacting the second side; and

[0012] moving the first element with respect to the second element so asto skew the spine by moving at least one of the first side in the firstplane and the second side in the second plane.

[0013] The present method advantageously permits creation of a skewedspine, which can be advantageous in reducing chip out in trimmingdevices, for example.

[0014] Preferably, the method further includes trimming the skewedspine. The skewed spine may form a skew angle with respect to the firstplane, the skew angle preferably being an acute angle. The trimming mayproceed from the first side to the second side. The acute skew anglereduces the chipout effect of the trimming.

[0015] The present invention also provides a clamp having a firstclamping element, a second clamping element for clamping a bound book,and an actuating device moving the first clamping element with respectto the second clamping element to create a shearing force in the book.

[0016] The present invention also provides a trimmer having a blade anda clamp according to the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017]FIG. 1 shows a force analysis of a prior art blade edge cuttingthrough a top section of a vertical book spine; and

[0018]FIG. 2 shows a force analysis of a prior art blade edge cuttingthrough the bottom of the vertical book spine of FIG. 1.

[0019] Three preferred embodiments of the clamping device of the presentinvention are described below by reference to the following drawings, inwhich:

[0020]FIG. 3 shows one embodiment of a trimmer having a first embodimentof a clamping device according to the present invention;

[0021]FIG. 4 shows a the FIG. 3 embodiment with the trimmer bladedescending;

[0022]FIG. 5 shows a second embodiment of a clamping device accordingthe present invention;

[0023]FIG. 6 shows a third embodiment of a clamping device according tothe present invention;

[0024]FIG. 7 shows a schematic top view of the embodiment of FIG. 3; and

[0025]FIG. 8 shows a force vector analysis on the skewed spine.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026]FIG. 3 shows a first embodiment of an edge trimmer having aclamping device 50 with a first clamp element 52 and a second clampelement 54, which in this embodiment may be a horizontal stationary ormoving support. An untrimmed book 30 has a first side 32 defining afirst plane 42 and a second side 34 defining a second plane 44. Thesides 32, 34 may be formed by a cover for sheet material 36, the coverhaving a spine 38 with an adhesive 39 binding the sheet material 36.

[0027] Side 34 rests horizontally on clamp element 54, which isadvantageous as the book 30 is then in a stable position. Clamp element52 may then clamp first side 32 by moving in direction 53.

[0028] For example, clamp element 52 may be fixed to a rod 55 having acam follower 105 extending from the side of the rod 55. A piston 100pivotally attached to the cam follower 105 and at its other endpivotally to a fixed support may drive cam follower 105 to follow a cam112 in a cam support 110. As the piston extends cam follower 105 isdriven down the cam 112 in direction 53 so that clamp element 52 clampsbook 30.

[0029] As shown in FIG. 4, clamp element 52 may then move in direction57 as the cam follower 105 reaches a horizontal portion of the cam 112,so that a shear force F is imparted on first side 32, which moves alongplane 42. Second side 34 remains fixed on stationary clamp element 54,so that an acute angle theta is created between spine 38 and first plane42.

[0030] Actuating mechanisms other than the single piston/cam deviceshown in FIG. 3 are possible, for example a two piston device.

[0031] A reciprocating side trimming blade 60 with a blade edge 62 maymove in direction 64 to trim the sides of the book 30. As shown in FIG.8, due to the angle theta, the normal force FN on spine 38 created bythe force FR of blade 60 is increased, so that chipout may be reducedover most of the spine.

[0032]FIG. 7 shows a top view of the FIG. 3 embodiment, which showsedges 131 and 132 of book 30 extending past the clamp elements 52, 54,so that trimming blades 60, 160 may trim the edges 132, 131,respectively.

[0033] Clamping element 54 may be a moving conveyor as well, but arelative movement between elements 52, 54 is required to create theskew.

[0034]FIG. 5 shows a second embodiment of the clamping device of thepresent invention having a first clamp element 82 with a clamp pad 182and a second clamp element 84 with a clamp pad 184. The clamp elements82, 84 may be arms that clamp the book in a first motion and then slidewith respect to each other to create a differential movement whichcreates shear force F.

[0035]FIG. 6 shows a further embodiment of the present invention inwhich the clamping device of the present invention includes a firstclamp element 92 moving in direction 72 and a second clamp element 94moving in direction 74 (although direction 74 may be the same directionas direction 72, with clamp element 94 moving more slowly that clampingelement 92). Clamp elements 92, 94 thus may be moving conveyor beltsimparting a frictional force on sides 32, 34 respectively.

[0036] “Book” as defined herein may be any collection of sheet materialwith a spine. “Clamp element” as defined herein is any element providinga frictional force to the side of a book operative for moving the sideof the book.

What is claimed is:
 1. A method for producing a profiled spine in a bookhaving a first side defining a first plane, a second side defining asecond plane and a spine, the method comprising the steps of: clampingthe book using a first clamp element contacting the first side and thesecond clamp element contacting the second side; and moving the firstelement with respect to the second element so as to skew the spine bymoving at least one of the first side in the first plane and the secondside in the second plane.
 2. The method as recited in claim 1 furthercomprising trimming the skewed spine.
 3. The method as recited in claim2 wherein the book is horizontal when trimmed.
 4. The method as recitedin claim 2 wherein a blade first trims the first side, the first sideforming an acute angle with the spine.
 5. The method as recited in claim2 wherein the book is trimmed on two edges by two blades, the firstelement being locate between the two blades.
 6. The method as recited inclaim 1 wherein both the first and second elements move.
 7. A clampcomprising: a first clamping element; a second clamping element forclamping a bound book; and an actuating device moving the first clampingelement with respect to the second clamping element to create a shearingforce on the sides of the book.